Abstracts of student project reports: Uganda courses since 1998 OTHER INVERTEBRATES CONTENTS ANTS 1 BEETLES 6 DISTRIBUTION 9 OTHER INVERTEBRATES 14 ANTS Prevalence of ant repellents in floral scent in Kibale Forest National Park, Uganda Abstract Many plant species attract ant guards in order to reduce herbivory. However, this bears a potential disadvantage for the plant as ants could restrict pollinator access or damage pollen and floral structures and thus reduce reproductive success. Therefore it is crucial that plants develop mechanisms to keep ants away from their reproductive parts. One of these mechanisms is the use of volatile organic compounds to repel ants. This study looks at the prevalence of ant repellents in floral scent in a number of flowering plants. Findings indicate that plant species do not differ in their effect on ants‟ reactions but they all have a significant repellent capacity. This suggests that ant repellence may not only be present in ant-plant interactions but may be a widely used defence in many plant taxa. Martina Stocker, University of Vienna, Austria Màtyàs Viktor Farkas, University College London, UK Huw Richards, University of Edinburgh, UK 2012 Escape behaviour in ants (sub-family Formicinae) Abstract Predation is a major threat to foraging workers of ants. We investigated the role of different stimuli in inducing escape behaviour in a Formicine species common to Kibale Forest. We found that visual stimuli are not as important as vibrational stimuli and ants can modify their behaviour depending on the intensity of vibration. This allows the workers of the species to respond appropriately to the perceived threat level. João Pedro Pio, University of Lisbon, Portugal Nichola Plowman, University of St Andrews, United Kingdom 2010 Colony structure, range size and inter-species interactions in an arboreal ant species, Tetramorium aculeatum Abstract Tetramorium aculeatum is an arboreal ant species that builds felt nests on the leaves of Acanthus pubescens, an invasive shrublet abundant along forest paths in Kibale National Park, Uganda. Experiments found individuals from distant nests experienced higher levels of aggression than ants Page 1 of 19 Abstracts of student project reports: Uganda courses since 1998 OTHER INVERTEBRATES from the same bush as the focal nest when introduced to a focal nest. This contrasts with the introduction of individuals from nests on the focal bush that experienced similar levels of aggression to the control ant. Multiple queens were found in a number of nests suggesting this species is polygynous. Polydomy is therefore a likely explanation for the tolerance of individuals from nests on the same bush, with colonies covering entire bushes. DNA analysis would be required to determine relatedness between colonies. Nests of ant were found to respond more strongly and for longer to disturbances to their home branch rather than to neighbouring branches or from wafts of air. The strength and nature of responses suggests T. aculeatum may protect A. pubescens from larger herbivores, despite inconclusive evidence of any protective effect against small herbivores. Emma Blackburn, Imperial College London, UK Hannah Froy, University of Cambridge, UK Michelle Nesbitt, University of Nottingham, UK 2008 An investigation into the foraging strategies of Myrmicaria ants Abstract Optimal foraging is an area of intense investigation within behavioural ecology. The foraging behaviour of ants has been particularly closely scrutinised. We studied the applicability of the ideal free distribution model to, and the effect of different food processing levels on, recruitment of foraging ants of the genus Myrmicaria. The use of chemical cues in their foraging trails was also investigated. Recruitment of ants to food patches of different qualities was found to approximate to the ideal free distribution model. An intermediate level of food processing attracted the highest mean number of ants; whether food pieces were presented as clumped or dispersed patches also impacted on recruitment. Pheromones were not found to play an important role in Myrmicaria foraging trails. Judith Schleicher, University of Cambridge, Germany Oliver Pescott, University of Birmingham, United Kingdom 2006 Comparative foraging behaviour of ant species in primary and regenerating forest, Kibale National Park Abstract In the Kirindy Forest of western Madagascar the leguminous tree Albizia sp. supports mealy bugs whose honeydew in turn attracts ants and stingless bees. We studied the interactions of four species of ants and stingless bees foraging on this honeydew. The ant species appeared to partition the resource in time, with two species (Camponotus gouldi, Camponotus maculatus) being nocturnal, one (Paratrechina longicornis) being crepuscular and one (Monomorium destructor) mostly diurnal. Furthermore, numbers of bees (Liotrigona sp) and ants on the honey dew source were negatively related, with ants increasing in density with increased distance from the main trunk of the tree and bees showing the opposite trend. In conclusion we observed both a temporal and spatial separation of the different species of social insects foraging on honeydew. Faith Milkah Ngugi, Egerton University, Kenya Sinead English, University of Cambridge, United Kingdom 2004 Page 2 of 19 Abstracts of student project reports: Uganda courses since 1998 OTHER INVERTEBRATES Size structure and division of labour in driver ants (Dorylus sp.) in Kibale National Park, Uganda Abstract Our study investigated size distribution, population structure, and compostition of Dorylus sp. in Kibale Forest. We examined division of labour in foraging and nest-moving columns. Composition of prey was also studied. Dorylus columns show a size-frequency continuum, yet appear to be composed of two castes: „workers‟ and „soldiers‟. The worker caste could be split visually into two size classes, small and medium. Division of labour occurs in the column: medium workers are the main prey- carriers, small workers transport most larvae and pupae during migration and soldiers defend the column. The diet of Dorylus sp. consists of species from a broad range of invertebrate orders. Charmaine Uys, University of KwaZulu-Natal, South Africa Gráinne Foster, Trinity College Dublin, Ireland Samuel Guiton, Université Paris-Sud, France 2004 Factors affecting prey removal in trails of army ants (Dorylus spp.) in Kibale Forest National Park, Uganda Abstract This study was carried out in Kibale Forest to determine factors affecting prey removal in trails of army ants (Dorylus spp.). Trail properties were measured, then artificial pieces of prey of varying types and sizes were introduced into the trails and the responses noted. It was found that larger numbers of ants in the trail took longer to remove prey items. Increasing prey weight resulted in increasing group weight of the ants transporting it and also in an increased removal time. Finally, larger ant groups had longer removal times. Katharine Bradley, University of Liverpool, UK Frederik Seelig, University of Bonn, Germany 2003 Interaction between ants and Macaranga schweinfurthii in three habitats of KNP, and its effects on herbivory Abstract Ants involved in mutualistic relationships with plants often protect their hosts from herbivory. In order to investigate whether this was the case with the ant Crematogaster and Macaranga schweinfurthii, leaves and stems from four plants in each of three habitat types were collected and analysed for herbivory, ants and herbivores. We found that herbivory differed significantly between plants and habitats, with plants in the river showing 1.75 times the herbivory found in the swamp and 3.41 times that in the garden. Total number of Crematogaster ants was however not significantly related to the herbivory level, with most ants encountered in the river valley. A number of possible explanations as to why this may be the case is put forward, such as that ants may be providing benefits other than protection from herbivory to the plants. Lubna Tagelsir Karamalla, University of Khartoum, Sudan Lucia Scodanibbio, University of Cape Town, South Africa 2002 Page 3 of 19 Abstracts of student project reports: Uganda courses since 1998 OTHER INVERTEBRATES Colony density, predation rates and other observations on Dorylus wilverthi in Kibale Forest National Park Abstract We estimated and mapped the colony density of Dorylus wilverthi in a 1 km2 plot in Kibale Forest National Park. The estimated density is 24 colonies/km2. Migration and raiding patterns of single colonies were also observed and mapped. A simple method for determining whether ants belong to the same or to different colonies was developed and tested. Recognition and response to pheromone trails by D. wilverthi was tested in an experiment, showing that soil with trails of both colony members and ants from different colonies was preferred to untreated soil. Feeding rates were calculated using empirical and theoretical methods and gave a conservative estimate of 74.16 g dry wt/hr/colony to 148.32 g dry wt/hr/ colony (empirical). Martin Wildenberg, Vienna University, Austria Andrew Jackson, Trinity College Dublin, Ireland 2001 Plant-ant interaction in Psydrax subcordata (Rubiaceae) and Crematogaster Abstract Ant-plant symbioses have been developed by an intricate co-evolution over a long time. It probably started as a parasitic relationship and is based on the ability of the ants to live on the plant. Often the plant provides cavities in branches where